A broad-band wide-angle scan matching technique for large environmentally restricted phase arrays

Numerical solutions for the problem of radiation from an infinite planar array of waveguide horns loaded at the aperture with a thick partially dielectric filled inductive step plus an external radome are presented. The analysis is applied to the problem of matching a practical array over a specified scan volume and frequency band. A technique from which the best possible initial match is obtained by varying the step width and thickness is presented. The final broad-band match is obtained with the aid of two thin capacitive irises located inside the waveguides. Experimental verification of the analysis and resultant computer program used for the design is presented in the form of waveguide simulator results. Three -plane simulators are used and comparison of theory and experiment is presented for different combinations of external and internal matching structures.